The invention relates to an attachment construction for the attachment of a woven filter mat to a press plate of a cocoa press, said filter mat being bent over at its peripheral edge, and the bent-over edge part being inserted into a groove in the press plate and fixed by means of a pressed-in cord.
A cocoa press comprises a series of pots and pressers which are supported on pull rods between a cylinder block and an end block, and which alternate. The pots are rings which can slide over part of a presser. Springs extend between the pots and a radially projecting flange part of the pressers. Fastened on either side of each presser are press plates, each of which is provided with a large number of bores running transversely to the surface thereof and debouching at the back of the plate in a system of round and radial grooves. This system is connected to discharge pipes for pressed-out cocoa butter. Each press plate is also covered with a filter mat which is woven from stainless steel wire. Disposed between two filter mats fitted opposite each other there is always a press chamber into which cocoa mass can be conveyed through infeed pipes. Through the sliding of the pots and pressers into each other, this mass fed into the press chambers is brought to high pressure, as a result of which the cocoa butter is pressed through the filter mat and via the said bores and the said system of grooves into the discharge pipes. Left behind between the filter mats of a press chamber is a filter cake of cocoa particles which has to be removed after each pressing. Here the filter cake is detached from the filter mat by a pot, with very great forces being exerted on the mat. Relatively thick mats (thickness from 1 mm to 1.5 mm) are often preferred because of their great strength. However, the attachment of such a thick mat to a press plate is expensive. One known method is to screw the finished edge of the mat by means of a specially shaped attachment edge to the peripheral edge of the press plate, in which process the edge of the mat is slightly bent. Another attachment method is to insert the peripheral edge of a relatively thick mat with little flexibility into a groove in a steel ring which is fastened to the press plate.